Gonad-gonadotrope interactions: plasma gonadotrophin levels and tumour induction in long-term castrated rats.
The patterns of gonadotrophin secretion in intact controls and in male and female rats castrated for up to 36 months were established utilizing specific radioimmunoassay methods. Plasma LH increased 14-16 fold and FSH rose 4-8 fold in rats of either sex in the first 30 day interval showed an additional 76% increase of LH in both sexes and increases in FSH of 32 and 61% in males and females, respectively. These levels were maintained for an additional 34 months. The number of hypophyseal gonadotrophin containing cells, studied by immunohistochemical localization techniques, increased following gonad removal in a pattern similar to that for the circulating hormones. Development of gonadotrophin secreting concentrations which suggests that the gonadotropes are uniquely resistant to tumourogenesis unlike mammotropes, thyrotropes, and corticotropes.
D000818:Animals; D002369:Castration; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D009374:Neoplasms, Experimental / Q000209:etiology / Q000378:metabolism; D010053:Ovary / Q000502:physiology; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D010911:Pituitary Neoplasms / Q000209:etiology* / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D013737:Testis / Q000502:physiology; D013997:Time Factors
D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone